Alternative methods for chilling beverages have been around for a while now, for people who like their drinks cold but without the watering-down effects of ice cubes. But artist Nate Cotterman has come up with a new one that’s actually built into each of his hand-blown glasses. The product is called the Rocks Cube Glass, with a chilling cube affixed to the base of the glass.

Rocks Cube Glass’ thermal properties allow it to hold a chill for short periods of time, so whiskey (or any other beverage) in a cold Rocks Cube Glass will stay that way for around 20 minutes – ideally, enough time for you to really savor and enjoy whatever it is you’re drinking. Of course, these glasses have an appeal that goes beyond mere functionality, as each one is blown by hand by the artist before it finds its way to you.

That kind of quality doesn’t come cheap – the Rocks Cube Glass costs $90 a pop, and takes about four weeks to deliver. You can check out the product here, or take a look at a few photos in the gallery below.